A liquid crystal panel used for a liquid crystal display device such as a liquid crystal television does not emit light, and thus a backlight unit is required as a separate lighting device. The backlight unit is arranged on a back side (a side opposite to a display surface) of the liquid crystal panel. The backlight unit includes a chassis, a light source, a reflection sheet, and an optical member (a diffuser sheet). The chassis has an opening on a liquid crystal panel side. The light source is arranged in the chassis. The reflection sheet is disposed in the chassis and configured to reflect light toward the opening of the chassis. The optical member is arranged at the opening of the chassis and configured to efficiently direct light emitted from the light source toward the liquid crystal panel. One example of such a backlight unit is disclosed in Patent Document 1.